VCE Chemistry 2023

Walkthrough of the 2023 VCE chemistry exam: what it assessed, strategy tips, and the common errors flagged in the official marker report.

Marks: 120
Time: 150 min
Authority: VCAA
Updated: 2026-05-29

Open the official PDF ->Official marking notes

What this paper assessed

The 2023 VCE Chemistry Units 3 & 4 examination drew across the VCAA study design:

Unit 3 - How can design and innovation help to optimise chemical processes? redox chemistry and electrochemistry (galvanic and electrolytic cells, $E^\circ$ , Faraday's laws), fuels and energy ( $\Delta H$ , calorimetry), and rate/equilibrium ( $K_{eq}$ , Le Chatelier's principle).
Unit 4 - How are carbon-based compounds designed for purpose? the structure, nomenclature and reactions of organic functional groups, reaction pathways and synthesis, analysis by spectroscopy (IR, NMR, mass spectrometry) and chromatography, and the chemistry of food (proteins, carbohydrates, fats).

The 2023 paper was calculation-heavy, blending theory with practical technique. Markers expected balanced equations with state symbols, the chosen relationship stated before the arithmetic, and answers to appropriate significant figures.

Structure and timing

The paper is 120 marks in 150 minutes, plus 15 minutes reading time.

Section A - multiple choice (~30 marks): target ~35 minutes (about 1.2 min/question).
Section B - short and extended response (~90 marks): target ~115 minutes at roughly 1.3 minutes per mark.

A 4-mark calculation deserves ~5 minutes. Use reading time to scan the multi-step calculation items. Reserve ~10 minutes at the end to check units, significant figures and state symbols.

Worked practice questions (exam-style)

Worked example

Question 1 (5 marks): A 0.500 g sample of an organic acid (molar mass $122\ \text{g mol}^{-1}$ , monoprotic) is titrated with 0.100 mol/L NaOH. Calculate the volume of NaOH required for complete neutralisation.

Moles of acid:

n(\text{acid}) = \frac{m}{M} = \frac{0.500}{122} = 4.10 \times 10^{-3}\ \text{mol}

For a monoprotic acid the ratio with NaOH is $1:1$ :

HA(aq) + NaOH(aq) \rightarrow NaA(aq) + H_2O(l)

n(NaOH) = 4.10 \times 10^{-3}\ \text{mol}

Volume of NaOH:

V = \frac{n}{c} = \frac{4.10 \times 10^{-3}}{0.100} = 0.0410\ \text{L} = 41.0\ \text{mL}\ (3\ \text{s.f.})

Worked example

Question 2 (5 marks): A galvanic cell is constructed from a $Zn^{2+}/Zn$ half-cell ( $E^\circ = -0.76\ \text{V}$ ) and a $Cu^{2+}/Cu$ half-cell ( $E^\circ = +0.34\ \text{V}$ ). Identify the anode, write the overall equation and calculate the cell EMF.

The more negative standard potential is oxidised: zinc is the anode (oxidation), copper the cathode (reduction).
Half-equations:
$\text{Anode: } Zn(s) \rightarrow Zn^{2+}(aq) + 2e^-$

$\text{Cathode: } Cu^{2+}(aq) + 2e^- \rightarrow Cu(s)$
Overall:
$Zn(s) + Cu^{2+}(aq) \rightarrow Zn^{2+}(aq) + Cu(s)$
Cell EMF:
$E^\circ_{cell} = E^\circ_{cathode} - E^\circ_{anode} = 0.34 - (-0.76) = +1.10\ \text{V}$

Worked example

Question 3 (5 marks): For the equilibrium $CH_3COOH(aq) + C_2H_5OH(aq) \rightleftharpoons CH_3COOC_2H_5(aq) + H_2O(l)$ , explain, using Le Chatelier's principle, how the ester yield changes if (a) more ethanol is added and (b) water is removed.

(a) Adding ethanol increases the concentration of a reactant. The system partially opposes this by shifting right, consuming the added ethanol and increasing the yield of ester.
(b) Removing water (a product) lowers product concentration. The system shifts right to partially replace it, increasing the ester yield.
In both cases the driver is a concentration change, and the position of equilibrium shifts to oppose the disturbance; $K_{eq}$ itself is unchanged because temperature is constant.

Common errors students made

Recurring errors in VCE Chemistry responses include:

Omitting state symbols, especially in ionic and electrochemical equations.
Mixing up the oxidising and reducing agents, or anode and cathode in cells.
Quoting a Le Chatelier shift without naming the driver and direction.
Drawing energy profile diagrams without labelling activation energy or $\Delta H$ .

Add these subject-specific traps:

Careless mole-ratio errors and failing to identify the limiting reagent.
Reporting answers to the wrong number of significant figures.
Misinterpreting spectra - confusing the information from IR (functional groups), $^{1}$ H NMR (proton environments) and mass spectrometry (molar mass/fragments).
Confusing acid strength with concentration.

How to use this paper

Sit Section A in 35 minutes and Section B in 115 minutes under timed conditions with the VCAA data book. Mark against the VCAA assessment report and answers (linked in the frontmatter), which explain common errors and high-scoring responses. Re-attempt every integrated calculation after a 48-hour gap, writing the balanced equation and stated relationship before any arithmetic. Build a one-page checklist (state symbols, significant figures, mole ratios, anode/cathode, spectral techniques) and tick it on every relevant item.

Use this paper well

Sit the paper under exam conditions (150 minutes, 120 marks).
Mark yourself against the official VCAA marking notes.
Compare against the Chemistry hub to find the syllabus dot points this paper tested.

What this paper assessed

Structure and timing

Worked practice questions (exam-style)

Common errors students made

How to use this paper

Use this paper well

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